全自动免疫磁珠分选系统检测沙门氏菌

目的研究全自动免疫磁珠分选系统对国标沙门氏菌检测方法的改进效果。方法从肉鸡专项监测中选取106份样品,采用全自动免疫磁珠分选系统和GB 4789.4-2010《食品微生物学检验沙门菌检验》进行沙门氏菌对比检测。与国标法相比,全自动免疫磁珠分选系统取消了SC和TTB增菌,经BPW增菌后直接使用系统富集目标菌并接种显色平板。结果免疫磁珠法阳性检出率为32%,国标法阳性检出率为31%,二者无显著性差异(P0.05)。但磁珠法取消了二次增菌的步骤,检测时间比国标法节省24 h,且平板上的单个菌落生长率和菌株特异性也更好。采用磁珠法检测的106份样品中,有34份样品检出可疑显色菌株,都有单个可疑菌落生长,最后均鉴定为目标菌沙门氏菌;采用国标法有38份样品检出可疑显色菌株,其中3份无单个可疑菌落生长经再次转种,最后有5株经鉴定为嗜水气单胞菌等干扰性杂菌,仅33株为目标菌沙门氏菌。结论全自动免疫磁珠分选系统特异性好、单个菌落生长率高且检测时间短,可以用于食品中沙门氏菌检验。

Detection of Salmonella by automatic magnetic activated cell sorting system

Objective To investigate the improvement effect of detection of Salmonella by automatic magnetic activated cell sorting systems. Methods A total of 106 samples were selected from chickens special monitoring. GB 4789.4-2010 Food Microbiological Examination: Salmonella and automatic magnetic activated cell sorting system were used for detection of Salmonella. Compared with GB method, automatic magnetic activated cell sorting system canceled the enrichment of SC and TTB, enriched target bacteria after BPW enrichment, and then inoculated color plates. Results The positive rates of automatic magnetic activated cell sorting system and GB method were respectively 32% and 31%, with no significant difference (P>0.05). While automatic magnetic activated cell sorting system canceled secondary enrichment step, it saved detection time for 24 h compared with GB method, and single colony growth rate and specificity of strain were better. Among 106 samples, suspicious strains with a single suspicious colony growth of 34 samples by automatic magnetic activated cell sorting system were detected, and all were identified as targets Salmonella. Totally 38 samples of suspicious strains by GB method were detected, of which 3 samples without single suspicious colony growth were turned again. At last 5 suspicious strains were identified as Aeromonas hydrophila and Morganella morganii, only 33 strains of bacteria were identified as Salmonella. Conclusion Automatic magnetic activated cell sorting system has good specificity, high single colony growth rate, and short detection time, which can be used for detection of Salmonella.